Hydraulic horizontal press with two series of multiple chambers for pressing with filter plates for very high production



Jan. 15, 1963 A. VITALI 3,073,238

HYDRAULIC HORIZONTAL PRESS WITH Two SERIES OF MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES FOR VERY HIGH PRODUCTION Filed Jan. 2, 1959 10 Sheets-Sheet 1 I 8; a o o 0 0 v \u o o 0 o r IN V EN TOR.

ZV DIVIO i mLl Jan. 15, 1963 A. VITALI 3,073,238

HYDRAULIC HORIZONTAL PRESS WITH TWO SERIES OF MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES Fnn VERY HIGH PRODUCTION l0 Sheets-Sheet 2 Filed Jan. 2, 1959 M. h A

Jan. 15, 1963 v A. VlTALl 3,073,233

HYDRAULIC HORIZONTAL PRESS WITH Two SERIES OF MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES FOR VERY HIGH PRODUCTION Filed Jan. 2, 1959 10 Sheets-Sheet 3 \o 0 Q g; I O 0 0 U 0 IN VEN TOR. flv-rom a I nL @244, am 1 an Jan. 15, 1963 A. VlTALI 3,073,238

HYDRAULIC HORIZONTAL PRESS WITH TWO SERIES OF 10 Sheets-Sheet 4 Filed Jan. 2, 1959 Jan. 15-, 1963 A. VITAL] 3,073,238

HYDRAULIC HORIZONTAL PRESS wITH Two sERIEs 0F MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES FOR VERY HIGH PRODUCTION l0 Sheets-Sheet 5 Filed Jan. 2, 1959 INVENTOR. IN- -10 W mu Jan. 15, 1963 vl'r 3,073,238

' HYDRAULIC HORIZONTAL PRESS WITH TWO SERIES OF MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES FOR VERY HIGH PRODUCTION Filed Jan. 2, 1959 v 10 Sheets-Sheet 6 Jan. 15, 1963 A. VlTALl 3,073,238

HYDRAULIC HORIZONTAL PRESS wITH Two SERIES OF MULTIPLE CHAMBERS FOR PRESSING wITH FILTER PLATES FOR VERY HIGH PRODUCTION l0 Sheets-Sheet 7 Filed Jan- 2, 1959 Jan. 15, 1963 A. VlTALl 3,073,238

HYDRAULIC HORIZONTAL PRESS WITH TWO SERIES OF MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES FOR VERY HIGH PRODUCTION Filed Jan. 2, 1959 10 Sheets-Sheet 8 IN VEN TOR. g vTo/wo T14 Jan. 15, A, Vl L I HYDRAULIC HORIZONTAL PRESS WITH TWO=SERIES OF MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES FOR VERY HIGH PRODUCTION Filed Jan. 2, 1959 10 Sheets-Sheet 9 INVENTOR. IN'ID/WO Jan. 15, 1963 r A. VlTALl 3,073,238

HYDRAULIC HORIZONTAL PRESS WITH TWO SERIES OF MULTIPLE CHAMBERS FOR PRESSING WITH FILTER PLATES FOR VERY HIGH PRODUCTION Filed Jan. 2, 1959 1,0 Sheets-Sheet 10 IN VEN TOR. gain/V10 I United States Patent Ofiice 3,073,238 Patented Jan. 15, 1963 3,073,238 HYDRAULIC HQRIZ'UNTAL PRESS WITH TWt) SERIES OF MULTEPLE CHAMBERS FOR PRESS- ING WlliH PETER PLATES FOR VERY HIGH PRODUCTKGN Antonio Vitali, Milan, Italy, assignor to Societa Per Azioni Macchine Per Llndustria Dolciaria Carle dz Montanari, Milan Italy, an Italian firm Filed Jan. 2, 1959, Ser. No. 784,539 Claims priority, application Germany Aug. 26, 1958 7 Claims. (Cl. l115) The present invention relates to a hydraulic horizontal press having two series of multiple pressing chambers with filter plates for high production.

Filter presses are already known, which are combined with a hydraulic press and are constituted by a series of cylindrical chambers carrying piston-shaped filtering plates constituting together with peripheral rings, the cylindrical pressing chambers, which are opened and closed concurrently with the reciprocal displacement of the peripheral rings and the filtering piston-shaped plates, respectively opened by means of axially movable stepped rods and closed by corresponding springs pushing the peripheral rings in order to bring them back to their starting position.

Presses of this already known type comprised a single series of multiple pressing chambers formed by the pairs of piston shaped filter plates and the related peripheral rings, constituting together the cylindrical pressing chambers, which pairs were co-axially mounted upon four rods fastened by their respective ends to corresponding heads and one of said heads comprised the piston with its relative hydraulic cylinder pushing the series of piston shaped filter plates.

It is also Well known that in the said type of presses feeding of the material to be pressed was effected by pumping the said material, which was in a more or less fluid state, under a relative initial pressure, the said matrial being next pressed into the series arranged cylindrical chambers by the effect of the pressure exerted upon the first piston of the said chambers by the hydraulically operated main piston and subsequently upon the remaining pistons following the decrease of volume of the said chambers, from which pressure chambers the expressed liquid was conveyed into a collection receiver, while the residual material cakes pressed in the said chambers in the form of discs were caused to fall by their own weight at the end of the pressure, taking care to open in unison the chambers of all units, which chambers after having been discharged were closed anew by means of thrust springs to form the cylindrical pressing cavities in order to permit the repetition of the operative cycle.

It is also well known that the efficiency of these presses is directly proportional, firstly, to the quantity of liquid extracted, i.e., to a certain minimum pre-established percentage of liquid left in the residual cake shaped pressed material and, secondly, to the time required for performing each operative extraction cycle of the residual pressed material. The press, conceived according to the resent invention intends, before all to simplify the functional and structural conception of the machine, as well as obtain a larger production in comparison with the presses of the type known up to date with the maximum grade of extraction of the liquid from the material to be subjected to pressing and the minimum of overall dimensions required for the operation of the machine itself.

In fact, the presses of the type known up to the present time were very complicated and functionally deficient, resulting in a reduction of the production they should have given, besides the inconveniences presented by their maintenance. If, furthermore, a high production was de sired the presses became cumbersome, taking into account that the said presses had to be combined with other machines installed in the same building as, for instance boilers for the reduction of the pasty substance to an almost fluid condition, pre-chargers for the advance dosing of the quantities of the substance to be introduced into the pressing chambers, and other equipment completing the installation as a whole. In consideration of the fact that the press, according to the present invention is intended to operate at a rather high pressure, in order to obtain as high a degree of extraction percentage of liquid from the substance submitted to the pressing as possible, up to 7-8% of liquid present is attained in the residual material under a pressure of over 1000 kg. per sq. cm. upon the product. Simple and safe means are provided to ensure a long working life to the filtering plates, and a unique construction of the said filters is applied to the said plates so as to ensure a perfect filtering action as well as a ready and easy removal of worn or damaged parts.

The invention further provides a suitable pneumatically operating device for charging the fluid substance to be submitted to pressing in the cylindrical chambers, which device will ensure the required supply of the substance. With the said pneumatically operating device cooperates an automatically functioning device intended to prevent an excessive introduction of the said substance into the said distri'buter devices, as well as for regulating according to need the quantity of substance introduced into the said pressing chambers. x

The invention additionally provides a particular conception of a means for the reciprocal connection in series of all of the peripheral rings forming the cylindrical pressing chambers for the synchronous displacement of the said peripheral rings during the discharge phase, which rings are pushed under the thrust of helical compression springs in order to be returned to their normal position i.e. to form again the cylindrical pressing chambers, ready to receive new material for pressing. V

I Further, the invention provides a simplification of the chain-like connecting means of all of the pistons so as to afford an easy inspection of any piston of the series.

The press conceived according to the present invention achieves all of these ends and others, and is essentially characterized by this, that it comprises two series of multiple pressing chambers, co-axially disposed and connected by a central body comprising the respective cylinders provided with their hydraulic thrust pistons for the respective filtering plate pistons of the multiple pressure chambers, which thrust pistons are so arranged as to exert in the same and in the opposite direction the thrust upon the pistons fitted with filtering plates belonging to the respective series o'f multiple pressing chambers, the said filtering plates being so constructed as to prevent the crushing of their relative filters despite the fact that they are subjected to a high working pressure, so as to ensure a complete and continuous filtering of the liquid extracted from the substance subjected to pressure, the said filtering plates being also so constructed as to be able to be quickly demounted and remounted, despite the high temperature prevailing during the working phase, suitable means being provided to assure a perfect seal between the pressing pistons and the inner face of their relative peripheral rings forming the cvlinclrical pressing chambers, into which chambers the substance is introduced through pneumatically operating charging devices, to which charging devices of each of the two series of multiple pressing chambers the substance arrives through corresponding telescoping collector ducts, the first pressing chamber (the one adjoining the hydraulic thrust piston) being connected with a conduit bringing the material from a single distributor device for the said two conduits for the concurrent feeding of the two series of apparatuses belonging to the corresponding series of multiple pressing chambers to be fed, the said distributor being assisted by a device for dosing the quantity of substance to be introduced into the pressing chambers: there being further provided simplified means for the reciprocal connection of the plates supporting the filtering plate pistons, which plates are arranged upon both faces of the said pressing pistons, and simplified means for the reciprocal connection of the platens supporting the peripheral rings. for forming the cylindrical pressing chambers.

These and other characteristics will now be fully described, relative to one form of a press conceived ac cording to the present invention and illustrated only by way of example, on the appended drawings, in which:

FIG. 1 shows, on a reduced scale, a front elevation of the press with a centrally located control panel;

FIG. 2 shows, on a larger scale and limited to only some pressing chambers, a repetition of FIG. 1 with the control panel shown by dash lines;

FIG. 3 is a top plan view of the press illustrated in FIG. 2;

FIG. 4 is a longitudinal sectional view taken along the line 4-4 of FIG. 3;

FIG. 5 is a top plan view of the press, the same being a repetition of FIG. 3, but partly in section, and showing the conception of tightening the press and the principal parts thereof;

FIG. 6 is an isometric fragmentary front view of the press according to the invention mainly consisting of two heads and one middle body connected by but two tierods;

FIG. 7 is a cross-sectional view taken along the line 7--7 of FIG. 4, taken across one of the pressure chambers and being to a larger scale;

FIG. 8 is a longitudinal sectional view through two adjoining chambers of the two series of chambers, the same being illustrating the characteristic conception of the filtering plate pistons with their cylindrical peripheral rings and their respective pneumatically operating charging devices for the introduction of the substance to be subjected to pressing;

FIG. 9 is a detail sectional view of the device for visually signalling the active or rest condition of the charging devices;

FIG. 10 is an elevational view on an enlarged scale of the device for regulating the introduction of the substance into the distributor group of the said substance to the charging devices;

FIGS. 11, 12, 13 and 14 show details of the filtering plate and, more particularly;

FIG. 11 is a partial elevational view of the filtering plate looking from the face opposite the one intended to receive the filters;

FIG. 12 is a cross-sectional view taken along the line 12-12 of FIG. 1;

FIG. 13 is an elevational view of the opposite face of the plate, i.e. the side intended to carry the filters;

FIG. 14 is an enlarged detail view of a portion of the filtering plate fitted with the filters and the associated sealing ring;

FIG. 15 is a fragmentary face view of the three filters; and

FIGS. 16, 17 and 18 show on a reduced scale some pressing chambers illustrating the three phases of working, comprising a complete working cycle, viz. cha ging, pressing and discharging of the pressed residual material cakes.

-With reference to the appended drawings (FIG. 1), the reference character A indicates the characteristic frame, comprising two identical series of units B B etc. having multiple cylindrical pressure chambers in this instance eleven for each series. The reference characters C C C indicate the pneumaticaly operating charging devices for the fluid substance H in the cylindrical chambers and which fluid is to be subjected to press- The reference character D indicates the group for the concurrent feeding of the two series of charging devices C for injecting the substance to be introduced into the multiple chambers and coming from a distributor D assisted by an automatically operating crnttol and regulation of the introduction or charging of the said fluid substance to be subjected to pressing in the said cylindrical chambers by filtering plate pistons as Well as by a device E for establishing the percentage of liquid to be expressed, the whole being described in detail hereinafter. Lastly, the reference character F indicates the telescoping kinematic connection for the pistons and the reference character G indicates the means for the reciprocal connection of the peripheral rings.

As noted heretofore, the press according to the invention includes a frame A comprising a simple central body 1 (FIGS. 1, 4 and 6) provided with two cylindrical chambers 22 for their associated hydraulically operated thrust pistons 3-3 belonging to the respective series of multiple pressing chambers B B etc. The frame further comprises two heads 4-4 respectively connected to the said central body 1 by corresponding pairs of tie-rods 5-5, the ends 6-6 of which are locked by threaded rings 7 and safety locking rings 8. The cylinder 1 has intermediate its ends an annular projection 2' forming the respective bottoms for the thrust pistons 3 and the chamber 9 common to both pistons, into which arrives the fluid under pressure through an aperture 10, for the concurrent operation of the two hydraulic pistons. Between the pressing head 11 of the said thrust pistons 3 and the fiat surface of the pressing piston 12 of the first pressing unit B is disposed a thick plate 13 apertured for heat dispersion.

The tie-rods 55 have multiple functions. As already pointed out they assist in securing the heads 44 to the central body 1. They also act as supports for the sundry units forming the two series of pressure chambers 14.

Each of these chambers is formed by its associated pressing piston 12 and its own peripheral ring 15 respectively unitary with corresponding supporting plates 16, 17 mounted for sliding movement along said tie-rods 5 by means of bushings 18, 19 (FIG. 5).

As has been said, the filter plates carried by the pressing pistons 12 must ensure a perfect and continuous pressing operation in spite of their being subjected to pressures that may exceed 1000 kgs. per square cm.

The said filtering plates, generally indicated by the reference numerals 20 and 20 (FIG. 8) and associated respectively with the faces 21, 22 of each piston 12, viz. to the pressing faces 21 and 22 completing or closing each cylindrical pressure chamber 14 and are substantially alike, slightly differentiating from one another solely by their manner of anchoring to the respective faces 21, 22 of their respective pistons 12, the said plates 20, 20' being susceptible of sliding axially in a direction away from their corresponding seats as shortly will be explained, contrary to what has been done up to the present in the presses of this type wherein the said plates were immovably attached by screws to the faces of their respective pistons.

According to the present invention, each filtering plate 20, 20' is constituted of a heavy metal plate 23 (FIGS. 11 to 14) in combination with at least three metal discshaped filtering elements 24, 25, 26 (FIG. 14) received in the pressing face or filter carrier 27 of the said plates 20, 20' and respectively made of very close metal mesh, wide metal mesh and very wide metal mesh (see FIG. 15). The said filters 24, 25, 26 according to the invention, are held in place in a simple, practical way and are readily replaced on their respective filter carrying face 27 of the said filtering plates 20, 20'. In fact, the last (innermost) filter 26 and the next to the last (middle) filter 25 (FIG. 13) lie in a shallow recess 28 having the same diameter while the first (outermost) filter 24-, of very close metal mesh has a diameter substantially greater: than that of the other filters in order to permit the insertion of its periphery 24 into an annular seat 29 formed in the face 27 of the filtering plate 23 and locking it by means of a lead ring 30 forced into the seat formed by the three faces of the bent up periphery 24 of the first filter 24. On the face 28 bearing the third (innermost) filter 26 (FIG. 14) concentric annular grooves 31 are formed which are intended to receive the liquid yielded by the pressing, the said liquid being led, through passageways 32 into an annular hollow space formed by a shallow depression 34 in the face 34 of the plate 23 and by the faces 21, 22 of the piston 12 (FIG. 8). From the said annular hollow space the liquid flows into a collector conduit 35 formed in the body 36 of the piston 12 to enter a single evacuating draining duct 37 conveying it to a collector tank (not shown).

On the inner face 34 (FIGS. 14 and 8) of each filtering plate 23 there is formed an external annular step 39 in which a cork sealing ring 40 is located which ensures a lasting perfect liquid proof joint with the inner wall 41 of the peripheral ring 15. Because of the said sealing ring 40 a perfect and constant sealing action is ensured thanks to the possibility of an axial sliding movement given the filtering plates 20, 20, as before mentioned.

To this end both of the filtering plates 26, 26" have a central tapped hole 42 (FIGS. 8, ll, l2, 13) which engages the threaded end of a screw 43 biased to its rest position by a spring 44 which urges the plates 20, 20' into contact with the respective faces 21, 22 of the pistons 12.

The screw 43 associated with the plate 20 lying over the base 22 of the piston slides freely within a cupped axial bore 45 presented by the body of each piston 12 in such a manner that the spring 44 is seated on the bottom of the bore 45 and on the head of the screw 43 provided with a washer. With regard to the other filtering plate 2!) lying upon the pressing face 21 of the piston 12, the associated screw 43 is supported by a cup-shaped sleeve 46 in such a manner that the spring 44 is seated between the bottom of the sleeve and the screw head.

The sleeve 46 which supports and guides the screw 43 is in turn locked by a rod 47 housed in a seat radially formed in the body 36 of the piston, the inner end of said rod being intended for locking the cupped sleeve 46, while the other end is provided with means for screwing or unscrewing of the same, into and out of an associated seat formed in the body 36 of the piston. It is clear that in order to take down a filtering plate 20, 2t) constituting a plate 23 and a set of filtering elements 24, 25, 26 it is necessary to first demount the plate 26' and next the plate 211". Also for an eventual substitution of the sealing rings 46, the operation is rendered very easy and Quick thanks to the axial sliding of the respective filtering plates 20 and 20'.

Lastly, each face of the piston 12 is provided with a peripheral reinforced border constituted by a steel ring 48 (FIG. 8) arranged in an associated seat 49 formed in the body 36 of the piston which ring is intended to prevent a perimetral expansion due to the high pressure exerted by the resistance opposed by the substance pressed against the other filtering plate presented by the base face of the adjacent piston. Such a reinforcement shows great usefulness when one remembers that the press operates under a pressure of about 1130 kgs. per square cm. which is much greater than the working pressure of the common presses of this type.

As already observed, for each pressing unit B a pneumatically operated charging device C is provided which will be described later on, for the introduction of the fluid substance into the pressing chambers, each plurality of the said charging devices being fed by a distributor D of the fluid substance, assisted by a device D that assures a perfect and automatic operation, giving an absolute certainty of introducing with a constant pre- 6 cision into the chambers of the pressing cylinders the desired quantity of the pumped substance H.

To this end the said distributor D and device D comprise a hollow body 50 (FIGS. 2 and 4) in which the fluid substance is introduced by means of a duct 51 for passing from a distribution chamber 52 into a tube 53 common to both series of charging devices C, to be fed (FIG. 4). The tube 53 has two coaxial branches, one to each side of chamber 52, in each of which is disposed a freely telescoping tube 54 by means of which the substance is introduced into the devices C C etc. of each series. The charging devices C C etc. are series connected by a telescoping connector tube 55 which supplies the fluid substance H to the said devices.

Each charging device C C etc. is according to the invention constituted of a hollow body 56 (FIG. 8) provided with a chamber 57 communicating with the connector tubes 55 through which the fluid substance H is led into each charging device and a bore 58 in which sealingly slides a spindle 59 terminating in a smaller diameter valve stem 69 that cooperates with a valve seat 61 in the wall of each peripheral ring 15 that forms, with its related pistons 12, the cylindrical chamber 14. The upper end of the valve spindle 59 is provided with a cap 62 acting as a piston inside of an associated cylindrical chamber 63 formed inside a head 64 and biased upwardly by a spring 65. At the top of the head 64 are disposed two conduits 66 used for the introduction of compressed air or other fluid to act upon the head of the piston 62 when it is necessary to effect the closure of the valves 60, 61 and pass the fluid itself into the delivery pipe line 55 of the adjacent charging device and so on for the entire series, the fluid for actuating all of the devices being introduced into the chamber of the last one of them B by means of conduits 67 (FIGS. 1 and 2) connected to bodies 68 mounted on the two heads 4 of the press.

Each charging device C is fitted with a signal 69 (FIG. 9) to visibly indicate when the passage of the fluid substance H is closed, i.e. when the valve stem 60 is lowered. The signal 69 includes a pin 70 (FIG. 9) supported and guided by a body 71 and projecting with its end 70' toward the interior of the chamber 63 wherein slides the tapering base piston 62, which by descending forces the pin 70 to axially slide and move out with its end 7 0" from its supporting body 71, showing by this that the valve stem 60 obstructs the valve seat 61 for the fluid substance H in the cylindrical pressure chamber 14. A spring 72 biases the pin 7 0 to the resting position.

As mentioned earlier, the distributors D are assisted by a device D intended to prevent an excessive charging of the fluid substance to be pressed, as Well as regulate the quantity of the said substance introduced. To this end the same device serving for both of the pluralities of charging devices C is constituted by a valve 73 (FIG. 10) situated on top of the body 50 into which the substance H arrives through the pipe 51 from the distributor D, and from which body a pipe 74 leaves for discharging the excess fluid substance. the discharge phase, the lifting of the stem 75 of the valve 73, which stem actuates in turn a switch 76 controlling the electrical circuit (not shown) feeding the electric motor operating the pump delivering the fluid substance to the chamber 52 of the said distributor D, thus breaking the circuit of the said electrical motor and therefore halting the operation of the pump.

It is also possible, as has been mentioned, to regulate the quantity of fluid substance introduced into the pressing chambers 14 since the stem 75 of the valve 73 is axially adjustable so that by increasing or decreasing the stroke of the said stem in order to actuate the switch 76 one can either reduce or increase the quantity of fluid substance passing through the charging devices C on its way to the pressing chambers 14.

Due to the possibility of precisely obtaining a constant quantity of fluid substance H in the pressing chambers This excess causes during 14, the percentage of residual liquid left in the said extracted substance can be established with the same precision by means of the mechanism E (FIGS. 2 and 3) which is essentially based on the stroke eltected by each of the main pistons 3 that thrusts the pressing pistons 12 of the two series. For this purpose the first piston 12 of each series of pistons is provided, at its associated supporting plate 16 with an extension 77 to which is fixed the end 78 of a rod 79, while at the other free end 86 it is provided with a finger 81, which in advancing forwardly strikes an actuating element 82 of an electric switch 83. Said switch determines the interruption of the electrical circuit feeding the motor (not shown) opearting the pump delivering the fluid substance into the chamber 9, common to the two cylinders 2 of the hydraulic pistons 3, the said circuit being interrupted only when both fingers 81 will have completed their strokes. Thereby the movement of each thrust piston 3 of its associated series of pistons 12 is stopped and together with it all of the pistons 12 of the units or pressing chambers and, consequently, the pressing phase.

As mentioned previously, all of the supporting plates 16 for the filtering plate pistons are reciprocally connected by the telescoping spacing means F (FIG. 16) that constitutes a single operative structure, the last one of said means being secured to the inside face of its associated head piece 4 of the press (see FIG. 2). The said spacing means have a fixed stroke and are each constituted by two co-axial parts 84-85, respectively consisting of a hollow cylinder 84 and a stern 85 pivoted at 86 upon the arms of the supporting plates 16 of the pistons. The hollow cylinder 84 is provided with a plug 87 screwed into its open end. Said plug has an axial hole in which can freely slide the stem 85 of another hollow cylinder 84 that is the same as the hollow cylinder preceding it.

Each stem 85 is provided with a nut 88 at its free end to limit the stroke by abutment against the plug carrying the pivot of each hollow cylinder 84. The hollow cylinder 84 belonging to the piston 12 of the first unit B naturally has no stem 85 connected to its pivot 86, whiie the hollow cylinder 84 belonging to the piston of the last pressing unit B has its stem 85 fixed into the inner wall of its associated head piece 4.

All of the supporting plates 17 for the peripheral rings 15, and, therefore, the said rings, are also reciprocally connected by a chain system G, as already stated but, differently from the connecting devices F for the piston plates 16, the said peripheral rings being secured to one another only, and not to the frame of the machine, along the tie-rods of which they can freely slide.

The said chain system G is constituted of a plurality of metal strips 89 (see FIG. 16), all alike, and held at one end by a pin 96 fixed to the body oi the ring supporting plates 17, while the other end has an elongated slot 91 in which the pin of an adjacent supporting plate can slide.

The rest position of the pressing pistons 12, when the latter with the peripheral rings 15 form the pressure chambers 14 for the reception of the fluid material H to be subjected to pressing, is obtained by coil springs 92 (FIGS. 7 and 16) located between suitable seats respectively formed by the piston supporting plates 16 and the peripheral ring supporting plates 17. Said springs also serve to return the peripheral rings to their normal position after the discharge of the cakes of pressed material.

The press is completed by a pair of stepped rods 93 (see FIG. 16) extending freely through suitable bores 94 and 95 respectively provided in the plates 16 supporting the pistons 12 and the plates 17 supporting the peripheral rings 15. Said rods 93 have steps 96 forming abutments at each of the said supporting plates 17 for the peripheral rings 15, which abutments can be axially pushed by the said stepped rods 93 and caused to slide on the respective pistons until they are completely received on the latter in the pressed cake discharging phase (see FIG. 18). The first ring supporting plate 17 belonging to the first pressing unit B is pushed by the ends 93 (FIG. 5) of the said stepped rods 93, while the last two ring supporting plates 17 belonging to the two last pressing units B and B are caused to axially slide by the organs G reciprocally connecting the said plates 17.

The stepped rods 93 are hydraulically operated by having their heads 93" freely slidable like pistons, inside of glands 97 within cylindrical chambers 98 formed in each head piece 4 of the press, said chambers being closed by caps 99 (FIG. 5) into each of which the fluid under pressure is supplied by a collector pipe 100.

The reference numeral 101 (FIG. 4) denotes a valve for discharging the air operating the pistons 62 of the device C for the introduction of the fluid substance H.

After the foregoing description, the operation of the press according to the invention can briefly be summarized in the following phases:

Step I.Charging the Pressing Chambers 14 (FIG. 16)

Assuming that the groups of units B B etc. are in the positions shown in FIG. 8, i.e. with their cylindrical pressing chambers 14 arranged for maximum capacity, the introduction of the fluid substance H is started.

In this first step two operations are carried out concurrently. One operation concerns t-he expulsion of the air present in the chamber 63, i.e. upstream of the piston 62 (FIG. 9), for instance by means of the valve 101 which air holds down by its pressure the spindle 59, with the valve stem intercepting the entrance through the valve seat 61 of the fluid substance H into the pressing chambers 14. With the drop of air pressure upstream of the piston 62 the spring biases the latter upwards and therefore lifts the valve stem 60 oh the valve seat 61, thus allowing the fluid substance H to enter the pressing chambers 14. The second operation is to cause a pump (not shown) to start introducing the fluid substance H into the distributor body 50 and from this into the supply chamber 52 feeding both of the tubes 54 of the two symmetrical series of pressing units B B etc. and through the connector tubes 55 of each series of apparatuses B B etc. for the charging of the said substance into the sundry pressing chambers 14.

Pumping of the fluid substance H is automatically stopped by operation of the valve device D which valve begins to operate following the pressure increase taking place by the effect of the filling up of the chambers 14 and while the excess fluid substance is discharged by the overflow tube 74. Said valve operates to interrupt the functioning of the pump supplying the said fluid substance H.

At the same time there starts to operate an electrovalve (not shown) which is mountedon the control panel 102 (FIG. 1). The said electro-valve reestablishes operation of the air acting upon the pistons 62 and the charging devices C, in such a manner as to lower the valves 50-60 and therefor close the valve seat 61 for the passage of the fluid substance H into the cylindrical pressing cavities. With this terminates the first step.

Step II.Pressing (FIG. 1 7) is transmitted to the fluid material H in the associated pressing chambers 14 and by the latter to the bottom of the pressing pistons 12 iforming the adjoining pressure chambers 14 and so on chainlike up to the last pressure chamber 14.

Stopping of the advance of the two thrust pistons 3 is established in advance with relation to the percentage of residual liquid to be left within the pressed material.

For the foregoing purpose the device E enters in operation to regulate the percentage of the liquid to be extracted as hercinbefore explained by means of the rod unitary with the first piston 14, which latter when it reaches the pre-established pressing position initiates, with the finger 81 of the said rod the actuation of the electric switch 83 and the ensuing opening of the circuit feeding the motor actuating the pump introducing the hydraulic fluid into the cylinders of the two thrust pistons 3, which therefore stop their advance and consequently the pressing step comes to an end.

Step I1l.Discharge of the Residual Pressed Material (FIG. 18)

During this step the first operation consists in discharging the hydraulic pressure existing in the chamber 9 common to the two cylinders of the thrust pistons 3 that push the filtering plate pistons 12 and said hydraulic pressure is applied to the two cylinders 98 for actuating the stepped rods 93 which latter cause the opening of the pressing chambers 14 by axially pushing the supporting plates 17 for the peripheral rings 15 until the latter telescope over their relative pressing pistons 12, while at the same time the springs 92 which must return the peripheral rings back to their starting positions (FIG. 18) are loaded.

As clearly appears from the drawings (FIG. 16) the last two peripheral rings 15 are not pushed by the stepped rods 93, but by the effect of the kinnetic connection of the links 89 (the devices G).

Therefore, at the end of the travel of the said peripheral rings, the filtering plates 20, 20 are completely uncovered, which said plates form with the ring 15 the relative cylindrical pressure chamber 14 and therefore, through the space formed between the said filtering plates the residual cake-like pressed material H falls clear by its own weight.

Step I V.Clsing Step for Reforming the Pressing Chambers 14 (FIGS. 1-4) During this step, the elements forming the pressing units B B etc., as well as the cooperating elements, again assume the positions they held during the first step in order to reestablish the cylindrical pressing chambers 14 so that they again can be filled with new fluid material H.

To this end, first of all the pressure in the two cylinders f8 actuating the stepped rods 93 is relieved.

Consequently, the springs 92 expand to their rest positions and push the plates 17 supporting the peripheral rings 15 and the latter slide over their respective pistons 12 until they reassume their rest positions, taking into account that the pistons or the plates carrying the latter present opposing surfaces to the action of the springs 92, for they are anchored to an interior shoulder of their own head belonging to the frame of the machine.

Preferably, the material H to be subjected to pressure before being conveyed into the charging device D of the two series of pressing chambers 14 can be caused to pass through a volumetric doser of any type, a particularly useful one for the present press being designed to have a capacity of about 230 kg. of fluid material at a time, so as to have with certainty a constant quantity of material subjected to expression at each pressing operation.

Summing, up the press conceived according to the present invention offers many advantages over those of the type known up to the present, of which some are set forth below:

(1) constructional and operational simplification, such as to require but a minimum of parts suitable for series production, a minimum of personnel in comparison to that necessary for operating presses of the same type with an equal production, and restricted overall dimensions requiring a smaller space.

(2) The possibility of a maximum of pressing with a controllable percentage of liquid left in the residual pressed material.

(3) Ease of replacement of the filtering plates, the filters and the sealing felts of the pressing pistons. For the replacing of the filters it is only necessary to demount the lead ring 30, which can easily and quickly be done by prying up one of the two ends of the ring itself, lifting it, and taking the ring out.

To change the sealing ring 4% of the pistons, it suffices to bring the latter to the discharge position, in which it is an easy matter to introduce a lever for detaching somewhat the filtering plate from its resting surface over the piston face; it is then possible to Work on the cork ring or the cut ends thereof.

(4) Efficient and quick charging, with a guarantee of a constant quantity introduced into the cylindrical pressure chambers.

(5) The possibility of rapidly adjusting the quantity of fluid substances introduced into the pressing chambers, due to the valve device cooperating with the charging device.

(6) The possibility of establishing with precision the percentage of liquid to be left in the residual pressed material, due to the device connected to each hydraulic thrust piston which moves the pressing pistons.

(7) The possibility of having a fully automatic operatron of the machine due to the use of the aforementioned devices.

I claim:

1. A horizontal hydraulic press comprising a frame constituting a central body, two heads each spaced horizontally from said central body on opposite sides thereof, four tie rods in sets of two with each set of two tie rods rigidly fixing a different head to said body on a different side thereof, said body having cylindrical recesses formed therein each facing a different one of said heads, a different thrust piston disposed in each of said recesses for movement toward and away from the facing one of said heads, a different linear series of a plurality of pressing chambers between said body and each of said heads, each of said chambers being defined by a peripheral ring and a pair of filter plates, a different plate supporting each different peripheral ring, means supporting said filter plates, said last-named means including a different plate located between each pair of ring supporting plates and between the innermost of the rin supporting plates and the adjacent thrust piston, each of said filter plate supporting plates carrying a piston on one side thereof in positron to fit within the adjacent peripheral ring, said pistons all facing in one direction, said filter plate supporting plates each supporting a filter plate on the face of its associated piston and another filter plate on its other face, a filter plate on the inner surface of each said head, said tie rods slidably supporting the ring supporting plates and the filter plate supporting plates in coaxial alignment and guiding said ring supporting plates and said filter plate supporting plates for slidable movement toward and away from one another, fluid inlet means into each of said pressing chambers, fluid outlet means in each of said filter plates, means for concurrently supplying liquid under pressure from a common source to all the fluid inlet means and thence into the pressing chambers of each series of pressing chambers, means responsive to the pressure of the liquid in said pressing chambers for automatically cutting off said liquid supply, a different stepped rod slidably supported in said frame alongside each different series of pressing chambers, each said stepped rod being engageable with said ring supporting plates for moving said rings axially over an adjacent filter plate carrying piston for opening the periphery of each said pressing chamber for the discharge of a residual cake therefrom, the liquid inlet means into the pressing chambers being openings formed through the peripheral rings defining the same, and pneumatically controlled means for opening and closing said liquid inlet means through each of said peripheral rings, said means comprising a valve seat formed in said inlet opening, a hollow body mounted over said opening with its interior in register with and connected to said inlet opening, a rod reciprocable within said hollow body, said reciprocable rod having an inner end forming a valve closure for said valve seat, and an outer portion forming a piston, resilient means normally maintaining said rod in retracted position from said inlet opening, and means connected to a source of air under pressure for admitting said air into said hollow member over said piston end of said reciprocable rod.

2. A press according to claim 1, wherein each but the said hollow body of the outermost of said pressing chambers is provided with a liquid inlet and a liquid outlet and a telescopic conduit connects the liquid outlet of each of said hollow bodies with the liquid inlet of the hollow body of the adjacent pressing chamber.

3. A press according to claim 1, wherein means are provided, visible from the exterior of at least one of said hollow bodies, indicating the position of said reciprocable rod within said hollow body relative to said inlet opening, said means comprising a tubular chamber extending from said hollow body in normal relation thereto, said chamber being connected to the interior of said hollow body and being open at its other end, said chamber having a piston pin disposed recipro'cably therein, the portion on the outer end of the reciprocable rod having radially inwardly tapering sides, said piston pin having its inner end extendable into said hollow body adjacent said portion for engagement by its said tapering sides for outward movement upon depression of said rod into inlet closing position, and resilient means normally tensioning said piston pin toward the interior of said hollow body.

4. A press according to claim 1, wherein said hollow bodies are each provided with an air inlet and an air outlet, said air outlet opening of each said hollow body connected to the air inlet opening of the hollow body of the adjacent pressing chamber, the air inlet opening of the hollow body of one end pressing chamber of said series connected to a source of air under pressure and the air outlet opening of the other of the end pressing chambers of the series provided with an air outlet valve.

5. A horizontal hydraulic press comprising a frame constituting a central body, two heads each spaced horizontally from said central body on opposite sides thereof, only four tie rods in sets of two with each set of two tie rods rigidly fixing a different head to said body on a different side thereof, said body having cylindrical recesses formed therein each facing a different one of said heads, a different thrust piston disposed in each of said recesses for movement toward and away from the facing one of said heads, a different linear series of a plurality of pressing chambers between said body and each of said heads, each of said chambers being defined by a peripheral ring and a pair of filter plates, a difierent plate supporting each difierent peripheral ring, means supporting said filter plates, said last-named means including a different plate located between each pair of ring supporting plates and between the innermost of the ring supporting plates and the adjacent thrust piston, each of said filter plate supporting plates carrying a piston on one side thereof in position to fit within the adjacent peripheral ring, said pistons all facing in one direction, said filter plate supporting plates each supporting a filter plate on the face of its associated piston and another filter plate on its other face, a filter plate on the inner surface of each said head, means for mounting each filter plate for limited axial displacement away from its associated supporting plate, resilient means for biasing each filter plate toward its associated plate, said tie rods slidably supporting the ring supporting plates and the filter plate supporting plates in coaxial alignment and guiding said ring supporting plates and said filter plate supporting plates for slidable movement toward and away from one another, fluid inlet means into each of said pressing chambers, fluid outlet means in each of said filter plates, means for concurrently supplying liquid under pressure from a common source to all the fluid inlet means and thence into the pressing chambers of each series of pressing chambers, means responsive to the pressure of the liquid in said pressing chambers for automatically cutting off said liquid supply, and a different stepped rod slidably supported in said frame alongside each difiierent series of pressing chamhers, each said stepped rod being engageable with said ring supporting plates for moving said rings axially over an adjacent filter plate carrying piston for opening the periphery of each said pressing chamber for the discharge of a residual cake therefrom.

6. A press according to claim 5, wherein the filter plates are each provided with a stem, said stem fitting in a corresponding recess formed in its associated supporting plate, said recess housing a cup-shaped member having an opening formed in the bottom thereof, said stern passing through said opening and carrying a head at the inner end thereof, means retaining said cup-shaped member within said recess, and an expansion spring mounted over said stern intermediate the head thereof and the bottom of said cup-shaped member.

7. A press according to claim 5 wherein each filter plate comprises a metal disc provided on its opposite broad faces with concentric registered grooves connected to one another by a series of apertures traversing the thickness of the disc, filter discs resting on one broad surface of the metal disc, the other broad surface having a peripheral annular step, and a gasket freely seated on said step and slldingly and sealingly engaging the inner surface of the associated peripheral ring with which it forms a cylindri cal pressing chamber.

References Cited in the file of this patent UNITED STATES PATENTS 347,237 Grifiin Aug. 10, 1886 2,229,900 Reitz Jan. 28, 1941 2,253,437 Leimer Y Aug. 19, 1941 2,410,712 Cannon Nov. 5, 1946 2,714,849 Carver Aug. 9, 1955 

1. A HORIZONTAL HYDRAULIC PRESS COMPRISING A FRAME CONSTITUTING A CENTRAL BODY, TWO HEADS EACH SPACED HORIZONTALLY FROM SAID CENTRAL BODY ON OPPOSITE SIDES THEREOF, FOUR TIE RODS IN SETS OF TWO WITH EACH SET OF TWO TIE RODS RIGIDLY FIXING A DIFFERENT HEAD TO SAID BODY ON A DIFFERENT SIDE THEREOF, SAID BODY HAVING CYLINDRICAL RECESSES FORMED THEREIN EACH FACING A DIFFERENT ONE OF SAID HEADS, A DIFFERENT THRUST PISTON DISPOSED IN EACH OF SAID RECESSES FOR MOVEMENT TOWARD AND AWAY FROM THE FACING ONE OF SAID HEADS, A DIFFERENT LINEAR SERIES OF A PLURALITY OF PRESSING CHAMBERS BETWEEN SAID BODY AND EACH OF SAID HEADS, EACH OF SAID CHAMBERS BEING DEFINED BY A PERIPHERAL RING AND A PAIR OF FILTER PLATES, A DIFFERENT PLATE SUPPORTING EACH DIFFERENT PERIPHERAL RING, MEANS SUPPORTING SAID FILTER PLATES, SAID LAST-NAMED MEANS INCLUDING A DIFFERENT PLATE LOCATED BETWEEN EACH PAIR OF RING SUPPORTING PLATES AND THE ADJACENT THRUST PISTON, EACH OF SAID FILTER PLATE SUPPORTING PLATES CARRYING A PISTON ON ONE SIDE THEREOF IN POSITION TO FIT WITHIN THE ADJACENT PERIPHERAL RING, SAID PISTONS ALL FACING IN ONE DIRECTION, SAID FILTER PLATE SUPPORTING PLATES EACH SUPPORTING A FILTER PLATE ON THE FACE OF ITS ASSOCIATED PISTON AND ANOTHER FILTER PLATE ON ITS OTHER FACE, A FILTER PLATE ON THE INNER SURFACE OF EACH SAID HEAD, SAID TIE RODS SLIDABLY SUPPORTING THE RING SUPPORTING PLATES AND THE FILTER PLATE SUPPORTING PLATES IN COAXIAL ALIGNMENT AND GUIDING SAID RING SUPPORTING PLATES AND SAID FILTER PLATE SUPPORTING PLATES FOR SLIDABLE MOVEMENT TOWARD AND AWAY FROM ONE ANOTHER, FLUID INLET MEANS INTO EACH OF SAID PRESSING CHAMBERS, FLUID OUTLET MEANS INTO EACH OF SAID FILTER PLATES, MEANS FOR CONCURRENTLY SUPPLYING LIQUID UNDER PRESSURE FROM A COMMON SOURCE TO ALL THE FLUID INLET MEANS AND THENCE INTO THE PRESSING CHAMBERS OF EACH SERIES OF PRESSING CHAMBERS, MEANS RESPONSIVE TO THE PRESSURE OF THE LIQUID IN SAID PRESSING CHAMBERS FOR AUTOMATICALLY CUTTING OFF SAID LIQUID SUPPLY, A DIFFERENT STEPPED ROD SLIDABLY SUPPORTED IN SAID FRAME ALONGSIDE EACH DIFFERENT SERIES OF PRESSING CHAMBERS, EACH SAID STEPPED ROD BEING ENGAGEABLE WITH SAID RING SUPPORTING PLATES FOR MOVING SAID RINGS AXIALLY OVER AN ADJACENT FILTER PLATE CARRYING PISTON FOR OPENING THE PERIPHERY OF EACH SAID PRESSING CHAMBER FOR THE DISCHARGE OF A RESIDUAL CAKE THEREFROM, THE LIQUID INLET MEANS INTO THE PRESSING CHAMBERS BEING OPENINGS FORMED THROUGH THE PERIPHERAL RINGS DEFINING THE SAME, AND PNEUMATICALLY CONTROLLED MEANS FOR OPENING AND CLOSING SAID LIQUID INLET MEANS THROUGH EACH OF SAID PERIPHERAL RINGS, SAID MEANS COMPRISING A VALVE SEAT FORMED IN SAID INLET OPENING, A HOLLOW BODY MOUNTED OVER SAID OPENING WITH ITS INTERIOR IN REGISTER WITH AND CONNECTED TO SAID INLET OPENING, A ROD RECIPROCABLE WITHIN SAID HOLLOW BODY, SAID RECIPROCABLE ROD HAVING AN INNER END FORMING A VALVE CLOSURE FOR SAID VALVE SEAT, AND AN OUTER PORTION FORMING A PISTON, RESILIENT MEANS NORMALLY MAINTAINING SAID ROD IN RETRACTED POSITION FROM SAID INLET OPENING, AND MEANS CONNECTED TO A SOURCE OF AIR UNDER PRESSURE FOR ADMITTING SAID AIR INTO SAID HOLLOW MEMBER OVER SAID PISTON END OF SAID RECIPROCABLE ROD. 